E.
Electrofrog : In electrofrog turnouts the frog is full metal and is always live. It needs insulated rail joiners to be fitted at certain track positions.
Electrostatic Grass : Flock that simulates grass. A charge of static electricity makes the fibers stand upright.
Elevation : The measured height of a specific location above a base line.
EMU : Electrical Multiple Unit. A train consisting entirely of coaches, the outer of which have a cab enabling the train to be independently driven in both directions. An EMU is powered from an outside power source such as the overhead catenary or a third running rail.
End-To-End : The type of layout where your train starting at one end will eventually have to stop before it can be returned to it's starting point. This is where the "fiddle yard" comes in.
Epoxy : A two part resin and catalyst adhesive that cures rather than dries. The most useful for model building is the type that sets in 5 minutes, called "5-minute epoxy".
Expansion Joint : A special slip joint that includes an open space in the center to allow the rails to expand or contract.